Evaluation of in-house cefoxitin screening broth to determine methicillin-resistant staphylococci

Natkamon Saenhom; Rada Kansan; Peechanika Chopjitt; Parichart Boueroy; Rujirat Hatrongjit; Anusak Kerdsin

doi:10.1016/j.heliyon.2022.e08950

Evaluation of in-house cefoxitin screening broth to determine methicillin-resistant staphylococci

Heliyon. 2022 Feb 11;8(2):e08950. doi: 10.1016/j.heliyon.2022.e08950. eCollection 2022 Feb.

Authors

Natkamon Saenhom¹, Rada Kansan¹, Peechanika Chopjitt¹, Parichart Boueroy¹, Rujirat Hatrongjit², Anusak Kerdsin¹

Affiliations

¹ Faculty of Public Health, Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, Sakon Nakhon, Thailand.
² Faculty of Science and Engineering, Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, Sakon Nakhon, Thailand.

Abstract

Methicillin-resistant staphylococci (MRS), including methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MRCoNS), have a global impact as a public health threat contributing significantly to morbidity, mortality, and socio-economic costs. Accurate and rapid detection of MRS results in effective antimicrobial therapy, immediate patient isolation, dissemination control, and appropriate disinfection measures. Herein, we developed an in-house cefoxitin screening broth and compared it to the cefoxitin disk diffusion method and polymerase chain reaction (PCR) for the detection of MRS. Verification of this screening broth on 52 MRSA, 37 MRCoNS, 44 methicillin-susceptible S. aureus (MSSA), and 11 MSCoNS revealed greater validity for MRSA/MSSA than for MRCoNS/MSCoNS. The kappa coefficient of 0.87 was superior for determination of MRSA and MSSA, whereas it was 0.54, which was considered poor, for determination of MRCoNS and MSCoNS. Application of this assay to screen MRSA should be useful in clinical laboratories and hospital infection-control units.

Keywords: Cefoxitin; Coagulase negative; Methicillin; Staphylococci; Staphylococcus aureus.